# IMAP4 Protocol Details

Each mailbox can be set to support any client protocol, such as Internet Message Access Protocol version 4 (IMAP4). Follow this procedure to set up IMAP4 client support for a mailbox:

1. On the Exchange Advanced tab, click Protocol Settings.
2. Click IMAP4, and then click Settings.
3. To enable the protocol for this mailbox, select the Enable for mailbox check box. To disable the protocol for this mailbox, click to clear the Enable for mailbox check box.
4. To use IMAP4 protocol defaults for Multipurpose Internet Mail Extensions (MIME) encoding, default character set, rich-text format, public folders, fast message retrieval, and user delegation, select the Use protocol defaults check box. When selected, all remaining options in the IMAP4 Protocol Details dialog box are unavailable. To use settings other than the default, click to clear the Use protocol defaults check box.

   You can change the following settings when the Use protocol defaults check box is disabled:

   - To display the body of received messages as plain text, click Provide message body as plain text. To display received messages as hypertext markup language (HTML), click Provide message body as HTML.
   - In Default character set, click a character set.
   - To display rich-text format, such as color, bold, italic, and other rich-text attributes, click Use Microsoft Exchange rich-text format.
   - To view all available public folders, click Include all public folders when a folder list is requested.
   - Some IMAP4 clients require Exchange to report exact message sizes. By default Exchange increases the speed of message retrieval by approximating message sizes. Clear the Enable fast message retrieval check box to disable fast message retrieval to support e-mail clients that require exact message size reporting.
   - To enable a delegate user to access another user's mailbox to view personal folders in the other user's mailbox, click Make user a delegate.
5. Click OK to accept settings.